Explosive burglar-alarm.



Gul. NETH.

EXPLOSIVE BURGLAR ALARM.

APPucATmN FILED MAY 4. 1915.

1 ,1813,90-0. 4 Patented May "23, 1916.

mj W a Ji/j `UNITED sTaTEs PATENT oEEicE.

GEORGE J. NETH, OF DAYTON, OHIO, ASSIGNOR OF ONE-HALF 'IO ELMER ELLSWORTH MCFARLAND, OF DAYTON, OHIO.

EXPLOSIVE BURGLAR-ALARM.

' Application filed May 4, 1915.

To all whom t may con-ccm:

"='Be it known that I, GEORGE J. NE'ri-I, a

citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have inventednew and useful Improvements in Explosive Burglar- Alarms, o f which the following is a specilication.

This invention relates to new and useful improvements in explosive burglar alarms.

The object of the invention is to provide a simple and eflicient device which will sound an explosive alarm when a window or door to which the same may be attached, is opened by a burglar or other unauthorized person. The device may be readily secured to a window or door of a dwelling, barn, chicken house or other building, and even to a .freight car or automobile, to effectively alarm persons at a distance that an attempt is being made to enter the above named property for an unlawful purpose. The operation of they device produces an explosion sufficiently loud and clear to be heard at a great distance, thus providing a safeguardl and protection for buildings and cars that-are unoccupied at the time they are unlawfully entered. The preferred form of embodiment of my invention is illustrated in the accompanying drawings, of which- Figure l is a plan view of my device in position to be operated by a door. Fig. 2 isa side view of the same. Fig. 3 is a side view, partly in section, of the explosive device. And Fig. 4 is a detail plan view of the `slide for holding the cartridge in the barrel.

' Throughout the specication and drawings, vsimilar reference characters denote 'corresponding parts. In a detailed description of the preferred 'form of embodiment of my invention, l des- V'ignates a barrel constructed of suitable metal to withstand the explosionl of a blank cartridge 2 adapted to be inserted in the inner end of its longitudinal bore 3. Preferably integral with, and extending rearwardly from the top and bottom portions of the barrel 1, are two preferably flat bridge members 4 and 5 respectively, which vinclineqtoward each other at their outer ends to receive a longitudinal cylinder 6.

Preferably integral with the bridge member 5 and barrel 1, are short standards 7 and 8 respectively., which are integral with Specification of Letters Patent.

Patented May 23, 1916.

Serial N o. 25,830.

that portion of the stem 13 which projects beyond the cylinder 6, there is secured, by a pin 14 or other suitable connecting means, a knob 15. By means of this knob the plunger 12 may be drawn outwardly to compress between it and a shoulder 16 formed in the outer end of the cylinder 6, a coil spring 17 which encircles the stem 13 of said plunger. |The inner end of the plunger 12 terminates in a pointed head 18 which is adapted to strike the cap of the cartridge 2 with sufficient power to explode the latter, when by means .now to be described, the compressed spring 17 is permitted to exert its full force against said plunger.

Pivotally secured, by a screw 19 or other fulcruming means, to the standard 7, is a trigger lever 20 which is so formed as to cause its outer end 21 to normally extend in the path of a trip 22 tobe hereinafter described. The lever 20 has a vertical portion 23 and a horizontally disposed portion 24, the latter being vertically movable between two parallel guides 25-25 preferably integral-with, and extending upwardly from the bridge member 4. (See Figs. 2 and 3). Extending inwardly from the vertical portion 23 of the lever 20, is a locking or engaging portion 26, the outer end of which is'curved to conform to the periphery of the plunger l2 in engagement with which it 4is normally held by a spring 27. This spring preferably consists of a thin wire, the lower .end of which is adapted to bear against'the surface to which the base plate 9 is attached, the middle portion thereof is lcoiled around the shank of the screw 19,

.Said yshoulder is .drawn beyond it by the knob 15. Therefore, when the hand grip upon the knob 15 is released, the coil spring 17 which has just been compressed, will force the plunger 12 inwardly until its shoulder portion 29 engages the locking portion 26 of the lever 20, by which a further inward movement of the said plunger will be restrained until the said locking portion 26 is withdrawn from its path by means now to be described.

The base plate 9 is preferably attached, by means of the screws 11, to an upper corner portion of a door frame 30, in a position to bring the end 21 of the lever 20, in the path of the trip 22 attached as follows toa door 31. The trip 22 preferably consists of a fiat metallic piece having an outer beveled edge, and terminating at its lower end in two leg portions 32-32 the lower eX- tremities of which are enlarged to permit a pivot 33 to pass loosely through them. The lower ends of the leg portions 32-32 of the trip 22, are embraced between two supporting` members 34.--34 to which the pivot 33 is secured, said supporting members being integral with, and projecting upwardly from a base plate 35 firmly secured to the door 31 by screws 36-36- Coiled about the pivot 33 is a spring 37 the lower end of which engages the base plate 35, while the upper end thereof presses against the upper portion of the trip 22, to hold it in the path of the trigger lever 20. On the lower end of one of the leg portions 32 there is formed a toe 3S, which, through-engagement with the base plate 35, limits the downward movement of the upper end of the trip 22. (See Figs. 1 and 2). I do rnot wish to be limited to this form of trip for the trigger lever 20, as any other suitable one may be employed if desired.

When the door 31 is opened, the beveled edge of the trip will be moved thereby into engagement with the end 21 of the lever 20, said end having a concave under-surface and a convex upper surface to insure a smooth sliding contact with the beveled edge of said trip 22. During the outward movement of the door 31, the trip 22 will engage and elevate the end 21 of the lever 20, and when the door is closed, the beveled edge of said trip will be moved outwardly by the upper curved surface of the end 21 of said lever, until the latter is cleared, whereupon the trip 22 will be again forced into the path of said lever by the spring 37.

During the day, or at any other time when it is desired to pass in and out through the door 31 without sounding an alarm, the trip 22 will do nothing more than move the engaging portion 23 of the lever 20 in and out of contact with the periphery of the plunger 12. However, when it is desired to set the alarm, the knob 15 is pulled out to a point where the shoulder 29 on the plunger 12, will clear the engaging portion 26 of the lever 20; whereupon the spring 27 will force said engaging portion 26 against the curved periphery of the pointed head 18 and in the path of the shoulder 29 on said plunger. IThe knob 15 is now released from the grip of the hand, to permit the compressed spring 17 to force the shoulder 29 on the plunger 12, against the engaging portion 26 of the lever 20, by which a further inward movement of said Aplunger will be restrained until the end 21 of said lever is elevated by the tri-p 22. A cartridge 2 is now inserted in the bore 3 of the barrel 1, within which it is firmly retained by the following described mechanism.

aReferring to Fig. l, the numeral 39 -designates a preferably flat metallic slide having the outline of a staple. This slide is provided with leg portions 40-40, one of --which is adaptedto enter a -longitudinal groove formed between a flange 41 on the bridge member 1, and the upper portion of the barrel head, while the other leg portion 40 is ada-pted to enter a similar groove formed between a flange 42 on the bridge ymember5,=and the lower vportion of the barrel head. yFormed on the head of the slide 39 is a curved thumb piece 43, by means of which-said slide may be moved into and out of saidl grooves with ease. After the cartridge 2 h as been placed within the barrel .1, the slide 39 is inserted within the aforementioned grooves. It `will now be observed from Fig. 3 that the legs/10 of said slide are of sulicient width to cover a portion of the outer rim-of the cartridge head, at the same time leaving an ample opening for the cap in the latterto be engaged by the pointed head 18 of the plunger 12.

When the plunger 12 is held back by the engaging portion 26 of the lever 20, and the cartridge'2 is. in yplace Within the barrel 1 as described above, the device is in readiness to soundan explosive alarm when the door 31 is opened by a burglar or other unauthorized-person. Vhen. the door is so opened, the `bevelediedge of the trip 22 will engage and elevate thecurved end. 21 of the lever 20, which will withdraw the engaging, portion. 26 ofsaid lever from the path of the plunger 12, l whereupon thev latter will be shothby the compressed spring) 17, against 'the cartridge 2 vto explode the ank char e in the latter. This explosion will be su cientlyloud and clear to alarm persons at a distance; that the building containing the door y31 is being unlawfully entered.

" I do not wish to be limited to the details of construction and arrangement herein shown and described, and any changes or alterations may be made therein` within the scope of the subjoined claims.

Having described my invention, I claim: 1. In an explosive burglar-alarm, a barrel, a blank cartridge adapted to be inserted therein, a cylinder, means for mounting said barrel and cylinder in longitudinal alinement with each other on a stationary element, a plunger movable through said cylinder into contact with said cartridge, a stem for said, plunger, a spring coiled around said stem within the cylinder, a shoulder in the outer end of saidcylinder against which the spring is adapted to be compressed by said plunger, a bridge piece connecting the top portions of said barrel and cylinder, a lever having a locking portion adapted to hold said plunger against the compressed spring, and a horizontallydisposed end portion extending above and beyond said bridge piece, a vertical guide on the latter, for the horizontally 4disposed end portion of said lever, and a trip adapted to be carried by a movable element, into engagement with the said end portion of the lever, to cause the latter' to withdraw its locking portion from engagement with said plunger and thereby permit the latter to be forced by the compressed spring, into explosive contact with the cartridge, substantially as described.

2. In an explosive burglar-alarm, a` barrel, a base plate, a standard for supporting the barrel upon said plate, a cylinder, an upper and a lower bridge piece connecting said barrel and cylinder in longitudinal alinement with each other, a plunger in said cylinder havin a pointed head adapted to enga ge the hea of said cartridge, a stem for said plunger extending beyond the outer end of said cylinder, a knob secured to the outer end of said stem, a spring coiled around said stem within the cylinder, a shoulder in the outer end of said cylinder against which the spring is adapted to be compressed by the plunger when the latter is drawn outwardly by the knob, a standard between the cylinder end of said lower bridge piece and base plate, a trigger lever pivoted to said standard and having a curved end extending above and beyond the upper bridge piece, vertical guiding means on the latter, for said lever, a locking ear on said lever, a shoulder on said plunger at the base of its pointed head, a spring secured to said standard for forcing said locking ear in the path of the inward movement of said plunger shoulder, and a trip adapted to elevate the curved end of said lever, to cause the latter to withdraw its lockingl ear from the path of said plunger and thereby permit said compressed spring to force the latter into explosive Contact with the cartridge, substantially as described.

In testimony whereof I have hereunto set my hand this 27th day of April, 1915.

GEORGE J. NETH. WVitnesses:

GEORGE C. NETH, WALTER V. SNYDER.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents. Washington, D. C. 

